So this is truth: About eight nanoseconds ago Williamsburg was the national-magazine-certified coolest hood in America, with more vaguely employed white hipsters per square inch than anywhere on the continent. There are 22 clubs and 61 art galleries and enough pubs pouring fine Belgian beers to pitch any 22-year-old into a state of bleary-eyed ecstasy.

Makis Antzoulatos was fine with all that.

But something nagged. As the neighborhood went hyper-hip and rents spiked, where would all the Puerto Ricans go? Or the old Poles who run the delis, and the Italians in East Williamsburg, where you can wander into a pasta joint at 11 p.m. and get a plate of scungilli and okay-but-slightly-headache-inducing Chianti?

Antzoulatos gathered pierced hipsters on the bare floor of his tenement living room and founded Gentrifiers Against Gentrification. They vowed to make common cause with Puerto Rican teachers and Italian bus drivers -- who, not incidentally, gave Williamsburg the working-class edge that made it hip in the first place -- and repulse the moneyed waves.

Whatever. Condos kept flipping. Antzoulatos dialed for a moving van.

"I realized the struggle was about negotiating the terms of departure," says Antzoulatos, 28, who now lives in a working-class precinct of slightly less rapidly gentrifying Boston.

Much has been written about gentrification and its discontents, but in few places has the speed and finality of that transformation been more startling than in Williamsburg, a formerly working-class Brooklyn neighborhood of 180,000 people along the East River. A wall of luxury glass towers is rising for 25 blocks along the "East River Riviera." Wander inland and check out the needle condo towers with three-bedroom places retailing at $1,135,000.

Overnight, another preserve of working-class American culture is rendered unaffordable to thousands of families -- and to the hipsters themselves. Want to know the next move? Toll Brothers, the nation's preeminent McMansion builder, has built a new luxe waterfront condo. Its ad features a preppy and distinctly unpierced blonde and the line: "Williamsburg, All Grown Up."

Anthropologist Neil Smith of City University's Center for Place, Culture and Politics has tracked gentrification with an obsession worthy of Ahab. He's charted the transformation of blue-collar neighborhoods, from Shaw in the District and San Francisco's Mission to the wharfs of London and the canal-lined streets of Amsterdam. This isn't the old block-by-block stuff, the grinding rehab of old rowhouses by scruffy young gentry. He's convinced he's found a new beast.

"We are witnessing the corporate and geographical restructuring of cities -- the wealthy are suburbanizing the center and pushing the poor to the fringes, and it's turbocharged," Smith says. "Artists are disposable -- developers just toss them out in hopes they'll colonize the next 'hot' neighborhood.